Université de Fribourg

Oxidation of sterols: energetics of C–H and O–H bond cleavage

Lengyel, Jozef ; Rimarčík, Ján ; Vagánek, Adam ; Fedor, Juraj ; Lukeš, Vladimír ; Klein, Erik

In: Food Chemistry, 2012, vol. 133, no. 4, p. 1435–1440

Phytosterols, as components of human diet, received much attention because of their cholesterol-lowering and antioxidant properties. We have theoretically studied sterols oxidation in terms of O–H and C–H bond dissociation enthalpies (BDE). In 17 Δ⁵- and Δ⁷-sterols, BDEs were obtained for reported sites of oxidation attack. Obtained results indicate that Δ⁷-sterols are more...

Université de Fribourg

Intrinsic distortion path in the analysis of the Jahn–Teller effect

Zlatar, Matija ; Gruden-Pavlović, Maja ; Schläpfer, Carl-Wilhelm ; Daul, Claude A

In: Journal of Molecular Structure: THEOCHEM, 2010, vol. 954, p. 86-93

The multideterminental-DFT approach was performed in order to calculate the Jahn–Teller (JT) parameters for the JT active molecules. Within the harmonic approximation the JT distortion can be analysed as a linear combination of all totally symmetric normal modes in any of the low symmetry minimum energy conformation, which allows to calculate the Intrinsic Distortion Path (IDP), exactly from...

Université de Fribourg

DFT Study of the Jahn-Teller Effect in Cu(II) Chelate Complexes

Gruden-Pavlović, Maja ; Zlatar, Matija ; Schläpfer, Carl-Wilhelm ; Daul, Claude A.

In: Journal of Molecular Structure: THEOCHEM, 2010, p. -

Density Functional Theory (DFT) in conjuction with the Intrinsic Distortion Path (IDP) is employed to study the Jahn-Teller (JT) effect in all four diastereoisomers of tris(ethylenediamine)copper(II) ([Cu(en)₃]²⁺) and tris(ethyleneglycol)copper(II) ([Cu(eg)₃]²⁺) complexes. As a consequence of the JT effect all the isomers tetragonally elongate to the C₂ configurations. Although there...

Université de Fribourg

Theoretical modelling of photoactive molecular systems: insights using the Density Functional Theory

Ciofini, Ilaria ; Lainé, Philippe P. ; Bedioui, Fethi ; Daul, Claude A. ; Adamo, Carlo

In: Comptes Rendus Chimie, 2006, vol. 9, no. 2, p. 226-239

An account of the performance of a modern and efficient approach to Density Functional Theory (DFT) for the prediction of the photophysical behavior of a series of Ru(II) and Os(II) complexes is given. The time-dependent-DFT method was used to interpret their electronic spectra. Two different types of compounds have been analyzed: (1) a complex undergoing a light induced isomerization of one of...